JP5018401B2 - Twin roll casting machine - Google Patents

Description

  The present invention relates to a twin roll casting machine.

  As a method for directly producing a strip from a molten metal, there is a twin-roll continuous casting method in which the molten metal is supplied between a pair of horizontally arranged rolls and the solidified metal is fed into a thin strip shape.

  6 and 7 show an example of a twin roll casting machine, which includes a pair of cooling rolls 1 arranged side by side and a pair of side weirs 2 attached to the cooling roll 1.

  The cooling roll 1 is configured such that cooling water circulates therein and the roll gap G can be adjusted in accordance with the thickness of the steel strip 3 to be produced.

  The rotation direction and speed of the cooling roll 1 are set so that the outer peripheral surface of each cooling roll 1 moves from the upper side toward the roll gap G at a constant speed.

  One side weir 2 is in surface contact with one end of each cooling roll 1, and the other side weir 2 is in surface contact with the other end of each cooling roll 1.

  A molten metal supply nozzle 4 is arranged between the pair of side weirs 2 so as to be located immediately above the roll gap G. The molten steel is poured from a ladle (not shown) to the molten metal supply nozzle 4, and the cooling roll 1 When molten steel is supplied to a space surrounded on all sides by the side weir 2, a molten metal pool 5 is formed.

  That is, when the molten metal pool 5 is formed and the cooling roll 1 is rotated while removing heat by circulation of the cooling water, the molten steel is solidified on the outer peripheral surface of the cooling roll 1 and formed on the outer peripheral surface of each cooling roll 1. The solidified shells 6 are stuck together, and the steel strip 3 is sent out below the roll gap G.

  At this time, a force is applied to a shaft box (not shown) pivotally supporting the neck portion of each cooling roll 1 in a direction approaching each other so that the plate thickness of the steel strip 3 becomes a target value.

  As the operating time accumulates, oxides containing manganese, silicon, and the like adhere to the outer peripheral surface of the cooling roll 1, and heat from the molten steel to the cooling roll 1 increases as the thickness of the adhesion layer of these oxides increases. This hinders the movement and delays the growth of the solidified shell 6 on the outer peripheral surface of the cooling roll 1.

  Therefore, a rotatable cylindrical brush 7 that is in contact with the entire length of the outer peripheral surface axial direction is disposed for each cooling roll 1, and the brush 7 is rotated in the same direction as the cooling roll 1 by a motor (not shown). The outer peripheral surface of No. 1 is polished to remove the oxide adhesion layer (see, for example, Patent Document 1).

  The portions of the brush 7 that are not in contact with the cooling roll 1 are individually covered by the cowling 8.

A plurality of dust suction ports 9 arranged in the axial direction of the cooling roll 1 are provided symmetrically in each cowling 8, and the dust suction ports 9 are connected to the exhaust blower 10 to prevent dust from being scattered due to the blasting.
JP-A-8-309488

  When attention is paid to the cleanliness of the brush 7 that cleans the outer peripheral surface of the cooling roll 1 over the entire length in the axial direction, the wire constituting the brush 7 and the dust remaining on the body portion are in the vicinity of the dust suction port 9. Although it is not recognized so much at α, it increases as the distance from the dust suction port 9 increases.

  The cleanliness of the brush 7 is reflected on the cooling roll 1, and a part of the dust remaining in a portion away from the dust suction port 9 of the brush 7 moves to the outer peripheral surface of the cooling roll 1, thereby moving the cooling roll from the molten steel. The heat transfer to 1 is hindered.

  That is, on the outer peripheral surface of the cooling roll 1, the solidified shell 6 grows smoothly at a portion where the range α in the vicinity of the dust suction port 9 of the brush 7 abuts, but dust impedes heat transfer at other portions. Due to this, the growth of the solidified shell 6 does not progress.

  Therefore, the steel strip 3 delivered by the pair of cooling rolls 1 is in a state in which the mountain portions where the generation of the solidified shell 6 shown in FIG. An unsolidified region remains in the valley portion between.

  Furthermore, in the steel strip 3 after the shrinkage due to solidification is completed, the thickness distribution in the plate width direction becomes uneven, and cracks may occur.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a twin-roll casting machine that can suppress unevenness in the thickness distribution of the strip in the plate width direction.

In order to achieve the above object, a twin roll casting machine of the present invention includes a pair of cooling rolls, a pair of side weirs, a molten metal supply nozzle arranged in a space surrounded by the cooling rolls and the side weirs, and an outer periphery of the cooling roll. Rotating brushes that contact each other over the entire length in the surface axial direction, and cowlings that individually cover the portions of the brush that do not contact the cooling roll, and a plurality of dust suction ports arranged in the cooling roll axial direction on one cowling. A plurality of dust suction ports arranged in the cooling roll axis direction on the other cowling, and the plurality of dust suction ports provided on one cowling and the plurality of dust suction ports provided on the other cowling are not symmetrically positioned. In this way, they are arranged so as to be shifted from each other in the cooling roll axis direction .

  Further, a configuration in which an exhaust blower is connected to each dust suction port and a flow rate adjusting means is provided between each dust suction port and the exhaust blower can be selected.

  According to the twin roll casting machine of the present invention, the following excellent effects can be obtained.

  (1) The position of a plurality of dust suction ports provided on both cowlings covering the brush for cleaning the cooling roll, with the cowling attached to one cooling roll and the cowling attached to the other cooling roll in the axial direction of the cooling roll Therefore, the crest portion of the solidified shell formed on the outer peripheral surface of one cooling roll faces the trough portion of the solidified shell formed on the outer peripheral surface of the other cooling roll, and the solidified shell formed on the outer peripheral surface of one cooling roll. Both the solidified shells can be bonded together in a state in which the trough portion faces the crest portion of the solidified shell formed on the outer peripheral surface of the other cooling roll.

  (2) Therefore, the thickness distribution in the plate width direction of the strip sent by the cooling roll tends to be averaged without being uneven, and the occurrence of cracks can be avoided.

  (3) If a flow rate adjusting means is provided between each dust suction port and the exhaust blower, the thickness of the crest portion of the solidified shell can be selectively increased or decreased as necessary.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 show an example of a twin roll casting machine according to the present invention. In the figure, the same reference numerals as those in FIGS. 6 and 7 denote the same parts.

  This twin-roll casting machine includes a columnar brush 7 that is in contact with each other over the entire length in the axial direction of the outer peripheral surface of each cooling roll 1 and a cowling 8 that individually covers a portion of the brush 7 that is not in contact with the cooling roll 1. ing.

  In the illustrated example, each brush 7 is disposed along the outer upper side of the corresponding cooling roll 1. Although not shown, each brush 7 has a configuration in which a large number of strands (for example, metal hairs) are provided at a substantially uniform density on the entire outer peripheral surface of a brush body formed in a substantially cylindrical shape, for example. Thus, by bringing each element wire into contact with the outer peripheral surface of the corresponding cooling roll 1, deposits such as oxides adhering to the cooling roll 1 are scraped off. Further, the central axis of the brush body (not shown) is arranged substantially horizontally (substantially parallel to the rotation center axis of the cooling roll 1), and is configured to rotate with the center axis as the rotation center axis. Yes. The rotation directions of the cooling rolls 1 are opposite to each other. The rotation direction of each brush 7 is the same as the rotation direction of each corresponding cooling roll 1 in the illustrated example.

  And one cowling 8 is provided with a plurality of (four in the illustrated example) dust suction ports 9 arranged in the axial direction of the cooling roll 1 (direction along the rotation center axis), and the other cowling 8 has the cooling roll 1 A plurality (five in the illustrated example) of dust suction ports 11 arranged in the axial direction are provided at positions offset in the axial direction of the cooling roll 1 so as not to be positioned symmetrically to the dust suction ports 9 of one cowling.

  The above description “not symmetrically” means that the dust suction port 9 attached to one cowling 8 and the dust suction port 11 attached to the other cowling 8 do not face each other in plan view. Even if it does not go so far, it mainly means that the positional relationship between the plurality of dust suction ports 9 and 11 is ensured to be shifted from each other in the axial direction of the cooling roll 1.

An exhaust blower 10 is connected to a dust suction port 9 provided on one cowling 8 via valves V02, V04, V06, and V08 as flow rate adjusting means, and a dust suction port 11 provided on the other cowling 8 is connected to the dust suction port 11. The exhaust blower 10 is connected via valves V01, V03, V05, V07, and V09 as flow rate adjusting means so that the air flow rates of the dust suction ports 9 and 11 can be adjusted independently. Each valve V02, V04, V06, V08 is provided so as to correspond to each dust suction port 9 one by one. Each of the valves V01, V03, V05, V07, V09 is provided so as to correspond to each dust suction port 11 one by one.

  During operation of the twin roll casting machine, the brush 7 is rotated in the same direction as the cooling roll 1 by a motor (not shown) to clean the outer peripheral surface of the cooling roll 1 to remove the oxide adhesion layer, The exhaust blower 10 is actuated to collect dust inside each cowling 8 (such as dust on the adhesion layer removed from the cooling roll 1 by the brush 7).

  When attention is paid to the cleanliness of the brush 7 covered with one cowling 8, the dust remaining in each part of the brush 7 is not so much recognized in the range α in the vicinity of the dust suction port 9, but it is so far away from the dust suction port 9. Since the dust remaining at a position away from the dust suction port 9 of the brush 7 moves to the outer peripheral surface of one cooling roll 1, the dust near the dust suction port 9 of the brush 7 is formed on the outer peripheral surface of one cooling roll 1. In the part where the range α comes into contact, the generation of the solidified shell 6 progresses more than the other part.

  That is, a crest portion of the solidified shell 6 (a portion where the thickness in the radial direction of the cooling roll 1 is thick) is formed on the outer peripheral surface of one cooling roll 1 at a portion where the range α near the dust suction port 9 of the brush 7 abuts. Thus, a valley portion of the solidified shell 6 (a portion having a small thickness in the radial direction of the cooling roll 1) is formed in another portion where the range α in the vicinity of the dust suction port 9 of the brush 7 does not contact. That is, in the axial direction, the crest portions and the trough portions are alternately formed (a state where the thickness of the solidified shell 6 is uneven).

  Further, when attention is paid to the cleanliness of the brush 7 covered with the other cowling 8, the dust remaining in each part of the brush 7 is not recognized so much in the range β in the vicinity of the dust suction port 11, but the dust suction. As the distance from the mouth 11 increases, the dust remaining at a position away from the dust suction opening 11 of the brush 7 moves to the outer peripheral surface of the other cooling roll 1. In the region where the range β in the vicinity of the suction port 11 abuts, the generation of the solidified shell 6 progresses more than the other portions.

  That is, the crest portion of the solidified shell 6 is formed on the outer peripheral surface of the other cooling roll 1 at the portion where the range β in the vicinity of the dust suction port 11 of the brush 7 abuts, and the range β in the vicinity of the dust suction port 11 of the brush 7. A valley portion of the solidified shell 6 is formed at another portion where the contact does not contact. That is, in the axial direction, the peak portions and the valley portions are formed alternately.

  Therefore, when the pair of cooling rolls 1 rotate at a constant speed, the solidified shell 6 generated on the outer peripheral surface of the other cooling roll 1 is formed on the crest portion of the solidified shell 6 generated on the outer peripheral surface of the one cooling roll 1. While the valley portion is bonded, the valley portion of the solidified shell 6 generated on the outer peripheral surface of one cooling roll 1 is bonded to the peak portion of the solidified shell 6 generated on the outer peripheral surface of the other cooling roll 1. It will be in the state. That is, even if the thickness of the solidified shell 6 before being bonded is uneven, the thickness of the solidified shell 6 is offset by the solidified shells 6 being bonded to each other in the roll gap G. It is possible to suppress unevenness in thickness. Moreover, it can prevent that a clearance gap generate | occur | produces in a trough part by pasting together so that a crest part may be inserted in a trough part. That is, the unsolidified region in the steel strip 3 can be minimized.

  Thereby, the thickness distribution in the plate width direction of the steel strip 3 after the shrinkage due to solidification is completed does not become uneven, and cracks do not occur.

  When the opening of the valves V02, V04, V06, V08 between the dust suction port 9 and the exhaust blower 10 is increased, the suction amount of each dust suction port 9 increases, so that the outer peripheral surface of one cooling roll 1 is increased. The cleanliness of the range α in the vicinity of the dust suction port 9 of the brush 7 in contact with is improved. In this case, in the range α, it is possible to more effectively prevent the dust from being transferred from the brush 7 to the cooling roll 1, and as a result, the solidified shell 6 is more easily generated more efficiently. Therefore, the thickness of the mountain portion can be increased. Further, when the opening degree of the valves V02, V04, V06, and V08 is reduced, the suction amount of each dust suction port 9 is reduced, so that the range in the vicinity of the dust suction port 9 of the brush 7 that contacts the outer peripheral surface of the cooling roll 1 is reduced. The cleanliness of α decreases. In this case, in the range α, the formation of the solidified shell 6 is suppressed, and the thickness of the peak portion can be reduced.

  If the opening of the valves V01, V03, V05, V07, V09 between the dust suction port 11 and the exhaust blower 10 is increased, the suction amount of each dust suction port 11 increases, so that the other cooling roll 1 The cleanliness of the range β in the vicinity of the dust suction port 11 of the brush 7 in contact with the outer peripheral surface is improved. In this case, in the range β, it is possible to more effectively prevent dust from being transferred from the brush 7 to the cooling roll 1, and as a result, the solidified shell 6 is more easily generated. Therefore, the thickness of the mountain portion can be increased. Further, when the opening degree of the valves V01, V03, V05, V07, V09 is reduced, the suction amount of each dust suction port 11 is reduced, so that the dust of the brush 7 in contact with the outer peripheral surface of the other cooling roll 1 is reduced. The cleanliness of the range β near the suction port 11 is lowered. In this case, in the range β, the formation of the solidified shell 6 is suppressed, and the thickness of the peak portion can be reduced.

  By adjusting the opening degree of the valves V01 to V09 and changing the amount of dust transferred to the outer peripheral surface of one cooling roll 1 or the outer peripheral surface of the other cooling roll 1, the thickness of the crest portion of the solidified shell 6 is selected. Can be increased or decreased automatically. That is, the thickness of the crest portion of the solidified shell 6 can be individually adjusted by individually adjusting the opening degrees of the valves V01 to V09. As a result, the thickness of the steel strip 3 can be adjusted more appropriately.

  The twin roll casting machine of the present invention is not limited to the above-described embodiment, and it is needless to say that changes can be made without departing from the gist of the present invention. For example, a strip produced in a twin roll caster is not limited to a steel strip. That is, the twin roll casting machine of the present invention can be used for manufacturing various metal strips.

  Further, the configuration of the brush 7 is not limited to the above embodiment. For example, although the rotation direction of the brush 7 is the same as the rotation direction of the corresponding cooling rolls 1, as shown in FIG. 3, the rotation direction of the corresponding cooling rolls 1 may be opposite to the rotation direction. good. The position of the brush 7 is not limited to the upper part on the outer side of the corresponding cooling roll 1, and may be disposed on the lower side on the outer side of the cooling roll 1, for example, as shown by a two-dot chain line in FIG. 3.

  In the above embodiment, the plurality of dust suction ports 9 and 11 are provided side by side in the axial direction of the cooling roll 1 (that is, provided at the same height), as shown in FIG. Moreover, the heights of the dust suction ports 9 and 11 may be different from each other. Also in this case, it is possible to form a state in which crest portions and trough portions are alternately formed in the axial direction of the solidified shell 6.

  In the above embodiment, one exhaust blower 10 is connected to the plurality of dust suction ports 9 and 11, but two or more exhaust blowers 10 may be provided. For example, as shown in FIG. 5, a configuration in which one exhaust blower 10 is connected to a plurality of dust suction ports 9 and another exhaust blower 10 is connected to a plurality of dust suction ports 11. Also good.

  Moreover, in the above embodiment, although the structure which adjusts the suction amount of each dust suction opening 9 and 11 by adjusting the opening degree of each valve | bulb V01-V09 was illustrated, the structure which adjusts suction amount takes this It is not limited to. For example, as shown in FIG. 5, the suction amount can be adjusted by adjusting the exhaust amount of the exhaust blower 10 connected to each of the dust suction ports 9 and 11.

  The twin roll casting machine of the present invention can be applied to the production of strips made from various metals.

It is a conceptual diagram which shows the position of the dust suction port in an example of the twin roll casting machine of this invention, and the relationship of the cross-sectional shape of a solidification shell. It is a conceptual diagram which shows the state which looked at the twin roll casting machine of FIG. 1 in the cooling roll axial direction. It is a conceptual diagram which shows the state which looked at other embodiment of the twin roll casting machine of this invention to the cooling roll axial direction. It is a conceptual diagram which shows the state which looked at other embodiment of the twin roll casting machine of this invention to the cooling roll axial direction. It is a conceptual diagram which shows the relationship between the position of the dust suction opening and exhaust blower in other embodiment of the twin roll casting machine of this invention. It is a conceptual diagram which shows the relationship of the position of the dust suction opening in the example of the conventional twin roll casting machine, and the cross-sectional shape of a solidified shell. It is a conceptual diagram which shows the state which looked at the twin roll casting machine of FIG. 6 in the cooling roll axial direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cooling roll 2 Side weir 4 Molten metal supply nozzle 6 Solidified shell 7 Brush 8 Cowling 9 Dust suction port 10 Exhaust blower 11 Dust suction port V01-V09 valve (flow rate adjusting means)

Claims (2)

A pair of cooling rolls, a pair of side weirs, a molten metal supply nozzle disposed in a space surrounded by the cooling rolls and the side weirs, rotatable brushes that contact each other over the entire length in the axial direction of the outer peripheral surface of the cooling rolls, and these brushes A cowling that individually covers a portion that is not in contact with the cooling roll, and provided with a plurality of dust suction ports arranged in one cooling ring in the axial direction of the cooling roll and a plurality of dust suctions arranged in the axial direction of the cooling roll in the other cowling A plurality of dust suction ports provided in one cowling and a plurality of dust suction ports provided in the other cowling are arranged so as to be shifted from each other in the cooling roll axis direction so as not to be symmetrically positioned. A twin roll casting machine.   The twin roll casting machine according to claim 1, wherein an exhaust blower is connected to each dust suction port, and a flow rate adjusting means is provided between each dust suction port and the exhaust blower.

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